Test pilot

Léon Lemartin, the world's first professional test pilot, by contract to Louis Blériot, August 20, 1910.
Jimmy Doolittle in 1928 with his Curtiss R3C-2, a year before he pioneered instrument flying
Chuck Yeager and the Bell X-1, first test pilot to break the sound barrier at Mach 1 in 1947
Neil Armstrong and the North American X-15 after a research test flight in 1960

A test pilot is an aircraft pilot with additional training to fly and evaluate experimental, newly produced and modified aircraft with specific maneuvers, known as flight test techniques.